Treehouse of Horror X

"**Treehouse of Horror X**"
"Treehouse of Horror X"
The Simpsons episode
Episode no.	Season 11; Episode 4
Directed by	Pete Michels
Written by	I Know What You Diddily-Iddily-Did:; Donick Cary; Desperately Xeeking Xena:; Tim Long; Life's a Glitch, Then You Die:; Ron Hauge
Production code	BABF01
Original air date	October 31, 1999
Guest appearances
	Tom Arnold as himself; Dick Clark as himself; Lucy Lawless as herself; Frank Welker as Werewolf Ned Flanders;
Episode features
Couch gag	Each member of the family dresses up as something from a previous "Treehouse of Horror" special, save for Lisa, who is an axe victim.
Commentary	Mike Scully; George Meyer; Ian Maxtone-Graham; Ron Hauge; Donick Cary; Tim Long; Matt Selman; Pete Michels
Episode chronology
← Previous; "Guess Who's Coming to Criticize Dinner?"	Next →; "E-I-E-I-(Annoyed Grunt)"
	The Simpsons season 11
	List of episodes

"Treehouse of Horror X" is the fourth episode of the eleventh season of the American animated television series The Simpsons, and the tenth annual Treehouse of Horror episode, consisting of three self-contained segments. It first aired on the Fox network in the United States on Halloween 1999. In "I Know What You Diddily-Iddily-Did", the Simpsons cover up a murder and are haunted by an unseen witness. In "Desperately Xeeking Xena", Lisa and Bart gain superpowers and must rescue Xena star Lucy Lawless from the Comic Book Guy's alter ego The Collector, and in "Life's a Glitch, Then You Die", Homer causes worldwide destruction thanks to the Y2K bug.

"Treehouse of Horror X" was directed by Pete Michels and written by Ron Hauge, Donick Cary and Tim Long. The episode contains numerous parodies and references to horror and science fiction works, including Doctor Who, I Know What You Did Last Summer and Battlestar Galactica. It also features actress Lucy Lawless and actors Tom Arnold, and Dick Clark as themselves. In its original broadcast, the episode was seen by approximately 8.7 million viewers, finishing in 34th place in the ratings the week it aired. Since its airing, the episode received positive reviews from critics.